Figure 2. Bmi1 can regulate the activity of the p16^INK4a promoter. The mRNA expression of p16^INK4a were determined by reverse transcription-PCR (A) and the protein expression of p16^INK4a were determined by western blot (B). p16^INK4a promoter or CMV promoter cloned into Luciferase vector were transfected into HCECs from young donor separately along with pCDNA3.1-Bmi1 or pCDNA3.1 (C). p16^INK4a promoter or CMV promoter cloned into luciferase vector were transfected into HCECs from old donor separately along with Bmi1-shRNA or control vector (D). Luciferase activity was measured 48 h after transfection.